Referring to FIG. 5, presently a conventional adjustable sofa chair may not be able to adjust to different positions when the sofa chair is positioned against a wall. That is, when a footrest extends forwardly while a backrest of the adjustable sofa chair is positioned against a wall, the backrest of the adjustable sofa chair may only move forwardly limitedly. And then when the backrest moves downwardly, the backrest moves downwardly and backwardly at the same time, which can cause the backrest to touch the wall before the backrest reaches its final position. Therefore, the adjustable sofa chair cannot be positioned against the wall completely, reducing space usage efficiency. The backrest of a conventional adjustable sofa chair may also not be able to move along with a person's back. When a person is in a sitting position, the person's back is at a sitting back position K, the person's head is at a sitting head position L. When the person is in a lying position, because the position of the chair does not change, the person's back is at a lying back position K′ and the person's head is at a lying heat position L′. There is a position shift U, which may cause discomfort.